17 relationship advice for beginner

I'm a 17 yr old guy, and i'm new to relationships and dating. I managed to get myself a wonderful girl to go to junior prom with. Before now i've just been too cynical to start looking for a relationship, but now i've found somebody i REALLY like. She's not horrible looking, in fact i'd say damn-well attractive, and our hobbies and interests match VERY well. We have friends in common and everything, but she is a freshman and i'm a junior. Whe have no classes together and the only time i see her is the few minutes between classes.

I don't even know what kind of terms we're on. so far the bigest progress i've gotten with her is asking her to prom and thats it. We've never kissed, not even held hands(one of the most typical of PDA),How does somebody advance a relationship like that?